Smoked wood?

I have been replacing the roof on our house, which was a clay tile roof supported by thin pine lathe boards (1x2s). The impetus for changing the roof is that many tiles were somewhat cracked and/or sagging because the lathe underneath in was semi-rotting/weak.

All of the chimneys have doors in the attach for cleaning out, and apparently some several decades ago one door got left open for some time and all of the beams and lathes near that door got completely blackened with smoke. These lathes seemed to be undamaged by the moisture related rot that had to some degree attacked most of the other lathes.

Anyway, I'm just throwing out there the possibility that smoking wood may provide some resistance to rot. Of course, maybe it doesn't actually and this part of the roof just held up well enough not to get as damp inside, I don't know.

I was in Newfoundland 30 years ago and witnessed a smoke house being used to treat wood siding and for the deck boards of a boat. It preserves meat and fish and the old guys who were doing it said that before bottled poisons were available that is how they treated lumber for outdoor use.

I remember seeing a TV show where wooden siding was passed over a flame to scorch it slightly. Archeologists often encounter charcoal at sites which are too wet to preserve wood so it is likely that a thin coating of charcoal affords some protection.

I volunteered at a prairie preserve a while ago, and we were replacing this split-rail fence and some of the original fence posts had been there for 50+ years and they were charred on their bottoms (pretty much any part that was in contact with the ground, and then a little bit higher). The only ones we had to replace were the ones the weren't charred. The charred ones didn't rot. The guy who was like my boss told me that this was a really common way that people used to preserve wood and that they'd probably last for a really long time.

I do not know where I first found this out, but it's a tradition that charring the in-ground portion of any wooden post of whatever species will double it's useful life, as compared to an uncharred post of the same age and species. The posts are charred just to the point of "checking"---that is, the surface breaking up into little squares, and then quenched. The wood is thus coated with a layer of comparatively rot-proof charcoal. I have also seen a plan for what was basically a pressure-cooker for bamboo made by welding several metal barrels together end to end with the ends removed. This is stood on it's end, filled with full length green bamboo, a small amount of water added to the bottom, and kept with the bottom in a fire for a few days. The hot steam and water are forced through the capillary system of the canes, percolating out a preservative liquor rather like creosote, which runs back down the inside of the tube and cycles through again multiple times. The heat alters the stuff and turns it into a preservative.....

I hate to sound like I'm boasting, but the crown post of my house has been in place since about 1450 and honestly looks new! Other parts of the building have an assortment of rot and pest traces (woodworm and death watch) but the parts which would have been exposed to the smoke from the open fire are in astonishingly good condition. The house became derelict during the early part of the 20th century, and suffered from a very damp situation, so a lot of the badly rotted wood was towards the edges of the house, but the interior beams where the fire could reach are rock solid with nary a wormhole. The house was rescued in 1960 and much old damaged wood replaced.

I should clarify - for the first hundred or so years of the house's existence it would have had no chimney, and the central hall would have been open up to the rafters and the crown post. The smoke would have accumulated up there and exited either simply between the tiles or through small gaps left for the purpose. THe fire would have been kept alive constantly. Bad for the lungs but good for the wood!

Best wishes, Rosalind

With greetings from Britain
Rosalind

Rosalind Riley

Posts: 70

Location: Kent, South-east England, UK

1

posted 5 years ago

1

... also just remembered reading a book on food archaeology which said that the remains of hazelnuts can be identified in Stone Age sites if they have been cooked by charring the shells. They actually last millennia! The professor in question has a library of charred food items and can recognise the species of plant or animal remains which have been cooked for food. High quality geekiness!

(The way to cook hazels is apparently to bury them in a shallow sandpit and burn a fire on top. Then you can carry your nuts around or store them against lean times. You can also eat more of them if they have been cooked - I mean they actually make better food as you don't get that claggy, I've-had-enough feeling in your mouth and you can get more protein and carbs in at a time. Veering off-topic there I fear.)

Wood will last for hundreds of years simply by keeping it dry. There is no need to treat wood with any kind of chemicals, wood smoke has lots of chemicals in it. Wood can even get wet if it can dry out. In other words as long as the wood dosen't stay wet it will not rot. It is a modern myth that wood has to be treated in order to not rot. There are many timberframe buildings in Europe that are 1,000 years old or more and they are just as strong and solid as the day they were built.

Of course you have to build smart and make sure you do not have a place that water can be trapped.

Smoked wood as a preservative is not a possibility, but a reality. Your observation are very astute and accurate. From the Minka of Japan, Hanok of Korean all the way to Slovakia, the wood of folk architecture is some of the best preserved in the world. The oldest, (undocumented,) domestic timber frame structure was a former bakery in Syria, parts of the structure date to over 7000 years old, and smoke from open fires contributed to this degree of preservation. As Rosalind noted, attics of old structure seem to be the best preserved, and some in Europe are coming close to a thousand years old. Of domestic architecture, the Middle East and Asian still have the oldest, built of stone, earth and timber frames of different combinations there of, many incorporating smoke or char directly or indirectly as a means of preservation. The Asian cultures have about a thousand plus years jump on European domestic and Spiritual Architecture, particularly timber frames, which benefited from the incorporation of this preservation technology, some in ways academics are just beginning to uncover. When done in a natural, more traditional way, the toxicity of these buildings and the techniques of using smoke and/or char, are safe for human habitation, only effecting fungal and pest issues. Alas, with modernization many have lost touch with these skills and the knowledge of there benefits. Most insurance companies would be none to happy to see smoke coming out from under eaves or the gable ends of a house they insure, but if done correctly it is very applicable for those of use that like traditional architecture and life skills. I'm hoping to design smoking chambers off two of my flues in the attic this coming year.

Rosalind Riley

Posts: 70

Location: Kent, South-east England, UK

1

posted 5 years ago

Hi again

While I'd agree with Aaron that dry wood is happy wood, I think Jay has a good point and would be interested to hear of any results of his experiments. Also, those 1000-year old buildings would certainly have had "smoke escape" going on rather than chimneys in their early years, which must contribute to the lack of pest damage which would otherwise have affected them.

Interestingly, some woods keep very well if they remain wet, such as the oaken piles under some very ancient, and very large, European stone buildings. I believe Winchester Cathedral was built on a peat bog which was then filled with wood (possibly alder not oak, their website is frustratingly uninformative on all of this but I think I remember this from visiting the building). It lasted well until the beginning of the 20th century, but subsidence meant that they had to send a diver down to shore it up with bags of concrete (an amazing feat, see http://en.wikipedia.org/wiki/William_Walker_%28diver%29). So there is something about stability of environment too, either wet or dry. Parts of the wreck of the Mary Rose, Henry VIII's flagship, survived under silt in the Channel - an anaerobic, wet environment. I do know that some of the pest-damaged parts of my house were dry, but unsmoked. Where the damp got to the lower timbers they simply rotted. (NB my house is all oak.)

Also - yes, smoke is toxic, but I don't think I'm in any danger from my smoked beams after all these years. I wish the outside of my house had been smoked - waaaaay too much maintenance there!

You are spot on about there being no chimneys. Smoke just rises up through many of the old wood frame structures of that time period, and still do today any many parts of the world. As noted earlier, smoked wood is not toxic, (unless you eat it.) You might also like to know, that in a Asia, particularly Japan, there is a siding style for country houses, where they take the vertical boards that will be the siding, and burn it black. This complete charring effect renders the wood well preserved. Rosalind, you mention maintenance of the outside; is your house painted? If so, why not choose one of the more traditional methods that are less labor intensive.

Andrew Ray

Posts: 165

Location: Slovakia

1

posted 4 years ago

Thanks for these further replies. I did not paint any of the wood I used in the attic with wood preservative, but now I do worry about wood worms affecting the soft, pine wood. Having just come again across this post, I'm going up to the attic right now to open the doors that are on the chimneys in the attic (and probably freak out the neighbours at the same time .

Andrew Ray

Posts: 165

Location: Slovakia

1

posted 4 years ago

On second thought I had while up there, I think I'll wait until installing some metal screen to prevent the small risk of a spark going up the chimney and starting a fire there!

Any thoughts on whether wood should be smoked before or after it has dried? I'm planning this year to get a neighbor to cut me boards on his saw mill for future projects here, and those boards will then need to sit a year or two to dry, so I'm thinking while they dry I could make some sort of shed/enclosure around them and smoke them at the same time.

Jay C. White Cloud

Posts: 2413

46

posted 4 years ago

Hi Andrew, welcome back,

Any thoughts on whether wood should be smoked before or after it has dried?

You could smoke them green, that would be fine, better yet use them green, that is how it was done. As a traditional timber wright, I work almost exclusivly in green wood.

I'm planning this year to get a neighbor to cut me boards on his saw mill for future projects here, and those boards will then need to sit a year or two to dry, so I'm thinking while they dry I could make some sort of shed/enclosure around them and smoke them at the same time.

You can just air dry it, if you really want to use dry wood, then open the doors on your chimney and "smoke your attic." Could you give us the town you live in? I would like to look it up, and if I'm in the area in the next few years, have a cup of coffee.

Regards,

jay

Rosalind Riley

Posts: 70

Location: Kent, South-east England, UK

1

posted 4 years ago

Hi Jay

I am catching up on a few old postings and saw that I had completely missed your last response/question to me - I am so sorry, how rude you must think me.

The exposed beams of my house were sealed/treated by the last owners, much to my horror as they changed it from a natural colour to a sort of uniform brown (I was living next door at the time). However, the house is over 500 years old and had gone through a period of extreme neglect, so I think I cannot blame them too much as I am sure they were acting under professional conservation advice. Quite a few of the timbers were replace in the 60s and there had been continuing problems with pests in the lower parts of the house. Actually the house looks lovely still! The walls are not painted. Because of its age, the house is subject to very stringent rules about repairs and maintenance to its external appearance.

Interested to hear more from Andrew about his preservation experiment!

Cheers

R

With greetings from Britain
Rosalind

Jay C. White Cloud

Posts: 2413

46

posted 4 years ago

Rosalind, you are not rude at all love, just busy like the rest of us. Nice part about the net, you can pick up or drop off many conversations. Unless someone needs something from me in a timely manner, I respond when I find the time to.

Okay, so charring wood and exposing it to smoke seem to be effective ways of preventing rot and woodworm attacks, and it seems that these techniques have been used in times before chemicals came into the picture. I'm really happy I discovered this thread because it confirms what I had instinctively assumed.

My question is: has anybody actually been using smoke in an existing wooden house in order to stop or prevent woodworm plague?

The background: my family owns a small cabin in the middle of a wood that was built in 1927. It's all wood, with thin walls and no central heating. Since it is only used on weekends and is sometimes left alone for months, it is basically defenseless against the moist air from the surrounding woods, except through its passive design (on top of a hill, with sufficient sunlight and ventilation holes).

It's got a woodworm infestation that is hard to treat, because most of the wood has been painted/varnished, which means sprayed insecticide cannot penetrate into the wood and will not stick to the outside for long either. We are currently in the process of solving one cause of this infestation (a basement moisture problem), but with its location in the woods, it feels like this house will always remain an open invitation to a lot of critters.

Up until the 1980s, it was fumigated every decade or so: completely wrapped in plastic, then pumped full of chemical nasty. That was evil but effective, and now it is evil, effective and illegal. So we're not doing that.

So I am really curious to know if it might make sense to just build a fire in the fireplace, choke off the chimney, and let everything be smoked through and through. Is it even doable (you'd be smoking and choking yourself as well)? Or are there more professional ways of going about this? Has anybody tried it? Will the house stink of smoke forever? Did it help?

Thanks for any suggestions!

Wytze

Jay C. White Cloud

Posts: 2413

46

posted 3 years ago

1

Hello Wytze,

I will do my best to address your query

My question is: has anybody actually been using smoke in an existing wooden house in order to stop or prevent woodworm plague?

It is hard to provide good sound advice for any species of Coleoptera (beetle) infestation (what is often generically misnomer of "Woodworm) without knowing the particular species...even though treatment modalities are very similar. The other, is the often false assumption that the infestation is actually...active...new...or not something else. The presence of holes and frass (saw dust) is the sign of emergence from pupated young adults...the infestation may be old and/or inactive. This can go on for sometime, yet in very old builds...what "appears new" may not be..

The shared information that the cabin was built in 1927, raises more questions than answers at this point...yet experience has demonstrated that this may not be an active infestation at all, so more questions/examination must take place to actually diagnose what may or may not be occurring.

Moisture can stimulate "new activity" yet this is rather uncommon in actuality, as wood typically (not always) for most species must be well above 20% in moisture (just new dead or living wood) to have a viable infestation. When you add the age of this wood, the fact that it is either painted/varnished, leaves me a tad wondering. As a former supervisor in Pest Control, I can share that many homes (minimum 60%) that I observed "tent fumigated" or otherwise...DID NOT...need the treatment as the SELLING company often insisted it did...this description sounds like another one of those...and there are other treatments that are less toxic to humans and the general environment.

Smoking was an ancient method of both direct treatment of wood (before and during construction) and then indirect by open hearth fires that vented through the eaves and attic of the architecture. This has been replace for the most part by (most similar method) "heat treatment" which can be effective...yet again...is often not warranted.

I can say, that in decades of studying and working on similar issues...I personally...have never seen an active infestation in "painted/varnished" wood of any age...new or old. Could you post photos of what you a believe indicates a new or active infestation? Can you get photos of the little "beasties" that you believe are infecting the wood. This may help solves this mystery a bit better. You could "smoke the house"...yes...but the results may render a miasma that many find unpleasant afterwords and the paint/varnish would be affected.

Thanks for your comment. It strikes me as odd that you have a hard time believing in active wood worm in older wood.

There's no doubt at all about the wood worm. It's been a recurring issue over the last few decades and we have most certainly not mistaken old holes for new ones. There's fresh powder below the holes in at least one new section of the house every few months.

Keep in mind this is a moist, Canadian-latitude country, and the house is smack in the middle of a woods. And it has no central heating, only a fireplace. And most of the time it is not used at all and boarded up. And as I mentioned, there are fundamental moisture issues. One of which is ground water soaking into the foundation walls, right up to the top where it also keeps the floor so moist that they have rotted through in a few points.

So I have no doubt that at least some of the time, the varnished wood is above 20% moisture. Besides, most of the planks are varnished only on the "public" side. And wood worms sure know how to find the unvarnished sides.

And if it has, I'm curious what you know about smoking/charring wood as a prevention measure. Cause that was what *I* am curious about.

Best regards,

Wytze

Jay C. White Cloud

Posts: 2413

46

posted 3 years ago

1

Hi Wytze,

I tried your link...and it did not quite work for me...sorry. I worked backwards from shared link and found this photo below...Hope it is the correct one for me to look at?

From the photo I see "emergence holes." This does not indicate an "active" nor ongoing infestation...not to say there isn't one per se. There are "dry wood" attacking Coleoptera more in Europe than we have here...yet this too is difficult to actually diagnose without "specimen examples" of the beetle type emerging from the holes.

I can share that I have examined many similar cases, and the "emergence holes" and frass from them was well over 100 years old and not any indication of current activity. If there are "new holes" finding a beetle to exam for identification should not be too difficult. There was reference to " new section of the house every few months," and that is additional areas to hunt. Most (all?) of these species larva attack and feed on "sapwood" not "heartwood" and this is why the use of "sapwood" is not allowed in parts of the EU.

HVAC generally has little effect on an infestation and they are deep inside the frame wood timbers and boards. Heat can actually stimulate them unless in the hundreds of degrees..."heat treatment" being a modern method of control...but very expensive. It does sound like there is a humidity level...yet the concept of "rising damp" is controversial.

This wood may be under attack from the moist areas where it is unfinished...very possible for a "drywood" species of beetle to lay eggs. For this I would suggest a borate or other topical treatment...or perhaps a "bore in" type treatment. Drywood species are a real challenge.

Smoking the wood for this level (should it be active) of infestation and species would not be generally effective...direct application of a chemical (natural or otherwise) is probably the most effective approach, and/or removal of all timber/boards that are predominantly "sapwood." I have done and/or facilitated many historic restorations over the decades and this is a troublesome issue many times where entire sections have to be replaced due to the level of damage...especially in structural timber frames.

Proper wood selection, and charring would have more effect in any new work...yet for a structure this old...I would consider "wood selection" and "wood treatment" over charring...just to honor the "historic fabric" and the ethos of "like for like" in historic restoration.

Jay, I've had success by using juniper oils on old houses timbers that were part sapwood and not practical to remove at the time I was working on them. Would you think that would be a viable treatment in this case?

Hmmm...I am sure it has a great deterrence from female bettls continuing to lay more eggs on a "choice timber," yet any "topical application," does not typically affect the larva inside doing the damage. In some (many?) cases this may not be an issue as the timber or board is not that heavily infected.

I have not ever had a good source for large quantities of "juniper oil." Where do you get it, and is it a "drying" or "non drying oil?

I extract my own from sacred cedar branches I prune, my land has many and I have been helping to keep them in good health since buying the land. The oil is a drying oil. I extract it with petroleum ether which evaporates slower than the other solvents, acetone or mineral spirits. I built a cold process tube extractor so I can extract from a whole branch or fill it with chopped up bits of branch. It takes approximately 10 lbs. of branches to extract one pint of oil, I do not evaporate the pet. ether from the oil completely since doing so would thicken the oil far to much for use in the spray rig. Petroleum ether is also not something I like putting into the air, so I run it in a distillation setup which keeps it out of the air. I use an airless spray rig, this allows the oil to penetrate aprox. 2 mm I am not trying to kill the existing larva which would require a pressure chamber to get full penetration. The treatment is for keeping adults from laying new eggs and it will keep other bugs away.

With that level of "alchemy" knowledge and experience, have you ever tried any of the more traditional "extraction methods" that do not employ a petroleum distillate? The one described is probably a benzine...which is pretty nasty stuff.

I also must confess a bit of confusion? I don't know of any of the essential oils of conifers to be "polymerizing" without the addition of a "true drying oil" such as flax, tung, etc. Is your treatment modality actually "polymerizing" of just a penetrating oil? If it is "polymerizing" what is the catalyst as I don't know of any natural ones for Coniferous other than the natural additives I wrote above.

Sorry, I forgot to put in that last post that I mix in a bit of pure linseed oil. usually about .5% to the cedar oil prior to dilution and application.

I have a BS in chemistry, I'm currently working on building a steam extractor that will incorporate the extraction set up I have now. Pet ether is indeed nasty stuff but not near as bad as the others, it is as explosive as hexane though and that is why I am converting to a steam extraction, not to mention, I won't have to worry about letting nasty vapors into the atmosphere, won't have to worry about blowing myself up when removing the pet ether from the oil either.